The present invention relates to portable collapsible scaffold structure, and particularly to such structure which is adapted to be supported in use upon and transported by a self-powered ground vehicle.
Vehicle-mounted extensible elevated work platforms are known in the prior art. One such prior art apparatus comprises a truck supporting thereon a swivel-mounted extensible turret arm, carrying at the distal end thereof a work platform in the form of a bucket, generally suitable for supporting one, or at most two workmen. These systems are highly maneuverable and generally are provided with controls at the bucket so that the supported workman can control his position, but the apparatus is designed for supporting at most two workmen in a very confined work space, which affords little room for equipment used by the workmen. While the apparatus is useful for work at a fixed point or location such as in telephone pole or sign repair work or in rescue work, it is unsuitable for carpentry, roofing, painting, brickwork or the like, where the workman must work along an extended work area, since the entire turret must be continually moved as the workman changes his position along the work area.
Collapsible vehicle-mounted scaffold structure is also known in the prior art, being disclosed, for example, in the U.S. Pat. No. 2,778,694 issued to M. E. Mitchell on Jan. 27, 1957 and U.S. Pat. No. 3,472,337, issued to G. L. Atchey on Oct. 14, 1969. In both of these prior art equipments, the scaffolding is supported in use directly above the vehicle and, therefore, the apparatus is limited to those applications wherein the vehicle can be driven underneath the work area. The Mitchell and Atchey devices could not be utilized for work along the outer wall of the building because the scaffold platform could not be positioned in use against the wall.